let income = 0;
let expenses = 0;

function recordIncome(amount) {
    income += amount;
    console.log(`收入记录: ${amount}`);
}

function recordExpense(amount) {
    expenses += amount;
    console.log(`支出记录: ${amount}`);
}

function showBalance() {
    console.log(`当前余额: ${income - expenses}`);
}

// 示例用法
recordIncome(100);
recordExpense(50);
showBalance();
